The present invention relates to a process for producing a laminate being built of at least two monolayers of polymeric tapes, a laminate being built of at least two monolayers of polymeric tapes and a panel made of the laminates according to the invention.
Laminates comprising polymeric tapes in multiple layers are known in the art. U.S. Pat. No. 5,578,370 discloses a mat of mutually intersecting elongate elements. The elongated elements may be produced from a polymeric film coated on both sides with a polymeric material having a lower softening temperature range than the middle, i.e. central layer. The thus obtained composite film is slit to form elongate elements in the form of tapes. The mat is then formed with the tapes by weaving, knitting or by laying down of a fibrous web. The mat is consolidated by heating the mat to fuse the tapes at least at their intersections. Prior to fusion a stack of two or more mats may be formed to obtain a product comprising at least two woven or knitted mats.
EP 1 627 719 discloses a multilayered polyethylene material and ballistic articles manufactured therefrom. The multilayered material comprises a plurality of monolayers of unidirectionally oriented polyethylene strips. The monolayers are crossplied at an angle with respect to each other. Before a second monolayer is formed over the first monolayer, the first monolayer is consolidated by applying pressure and heat. After aligning the strips of the second monolayer at an angle to the first monolayer a bilayered mat is formed by again applying pressure and heat. A multilayered material may be obtained by consolidating at least two bilayered materials obtained as described above.
EP 1 403 038 discloses a method for reinforcing an article by attaching to at least one surface of said article a tape, film or yarn. The tape, film or yarn can be formed of any drawn thermoplastic material. A drawn thermoplastic polymer of the AB or ABA type is preferred. The tape, film or yarn of the AB or ABA type is used in a form where the tape, film or yarn are at angle to each other.
The tapes according to prior art are therefore formed into a woven, nonwoven or knitted fabric. As an alternative the tapes are formed in unidirectional monolayers where the monolayers are crossplied at an angle to each other. The latter method makes consolidation of each individual monolayer necessary.